for some reason, the version of 1.0.3 that was in the 4.4 lite tree
was modified to allow shops with two doors -- this violates the spirit
of the game. with this diff, we revert back to classic 1.0.3 behavior.
Use const.
Add __noreturn__ attributes.
Add a __format__ attribute.
Add __unused__ attributes.
Use symbolic constants for open() and lseek().
Declare types of all function parameters; convert some function
definitions to ISO C form.
Ensure standard file descriptors are open on startup.
Check for errors writing output of makedefs.
Avoid duplicate definitions of variables.
